

@mastersthesis {6264,
	title = {Adsorption of hydrogen sulfide on fine rubber particle media ({FRPM})},
	year = {2013},
	note = {3566161},
	school = {Iowa State University},
	type = {phdPh.{D}.},
	address = {Ann Arbor},
	abstract = {A commercial rubber waste product, fine rubber particle media (FRPM), was found to adsorb hydrogen sulfide gas (H2 S) from biogas. Compared with traditional H2 S adsorbents, economic advantages make FRPM a potentially attractive alternative. A number of experiments were conducted to investigate fundamental information, surface properties, and breakthrough characteristics of these innovative adsorbents. The physical properties, composition and surface chemistry were investigated and compared with commonly available commercial H 2 S adsorbents, such as activated carbon and metal oxide, in order to compare performance and to assess the possible adsorption mechanism. The components of FRPM samples were similar to conventional tire rubber. The specific surface area was less than 1\% of activated carbon. The data supported that FRPM samples were particulate in nature with limited porosity. Infrared analysis and metal analysis experiments showed no direct evidence that the adsorption was a pure physical process. Analysis of experimental results and comparison to scientific literature suggest that two components contribute to the H 2 S adsorption{\textendash}carbon black and zinc. Fine rubber particle media (FRPM) derived from consumer waste sources, such as discarded vehicle tires, has been found to adsorb hydrogen sulfide (H2 S) from biogas. The challenge for FRPM reuse in biogas scrubbing applications is to increase its adsorption capacity so that it competes well with traditional adsorbents in terms of effectiveness and life cycle cost. In this research, zinc content, particle size, moisture content, temperature, and packing density were varied during H 2 S breakthrough tests. High zinc concentration and lower particle size increased the adsorption capacity of FRPM significantly while moisture content played an important role in the process. Additionally, H2 S removal by FRPM was optimized at a packing density of 75\% of the column volume, and the adsorption capacity increased with reactor temperature in a low range (20{\textdegree}C\~{}85{\textdegree}C). Two regeneration methods of spent FRPM were developed and tested. One efficient solution regeneration method using ZnCl2 solutions was evaluated in this research for its ability to recover FRPM{\textquoteright}s H 2 S adsorption capacity. Adsorption capacity recovery of FRPM following washing with a zinc solution (1g ZnCl2 /L) yielded an adsorption capacity of 120\% of the original. A half strength solution (0.5g ZnCl 2 /L) recovered 110\% of the adsorption capacity after the first wash and 80\% after the second wash. Thermal regeneration at a temperature of 80{\textdegree}C worked well in the first three regeneration cycles and reached approximately 100\% recovery. However, the regeneration capacity decreased with additional cycling. During thermal regeneration, at least 30\% of H 2 S adsorption capacity was attributed to physical adsorption, which occurred at room temperature.},
	keywords = {0543:Civil engineering, 0775:Environmental engineering, Adsorption, Applied sciences, Civil engineering, Environmental engineering, Fine rubber particle media, Hydrogen sulfide, Tire rubber},
	url = {http://search.proquest.com/docview/1417777951?accountid=14270},
	author = {Wang, Ning}
}
